Newby to cdr has prob writing .rm files

HiI have never used a cdr before. I have installed a cdr in my system. The software is Nero

The Question. I want to copy .rm etc video files onto cdr discs. When I used the Nero wizard I got to a section that was for vcd that told me I must first convert .rm to mpeg-1 . I get the impression that this is something to do with watching the video when the disc is in other machines, am I correct ?Can I just save the files as data files without haveing to convert ?